Among the greatest mysteries of the tropical rainforest are the pooping habits of sloths. Really. Those furry, slow-moving tree dwellers almost never descend from the safety of the tree tops—except ...

For years scientists assumed that sloths don't fart — believing the methane produced by their slow digestive system was simply absorbed into their bloodstreams and breathed out through their mouths.

Ground sloths occupied South America during the last ice age before going extinct 10,000 years ago. Scientists thought these giant creatures ate plants like their modern, tree-climbing counterparts.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Modern sloths hang ...

Sloths appear to have life figured out, and once the details are revealed, being envious makes sense. These tree-dwelling ...

Giant ground sloths have often been portrayed as gentle giants of the ice age. Much of their anatomy, from their flat molars to their vat-like guts, seems consistent with a diet centered around the ...